Recent research in the area of vibrotactile speech communication devices for the deaf shows that these devices can be beneficial to speech reception and language development in children. However, demonstrated gains are less than predicted by audiovisual analogies to tactile-visual perception. The goals of the proposed research are 1) To understand perceptual processes of cross-modal integration and attention in tactile-visual speech perception; 2) To study speech perception and lipreading during long-term use of a commercial tactile aid; and 3) To evaluate and model lipreading of sentences. Three projects are proposed. For Project I, in years 1-3, five experiments are designed to study tactile-visual and audiovisual integration of speech information and attentional processes in normal hearing and hearing impaired adults. In Project II, years 4-5, a wearable commercial vibrotactile aid will be used by 15 adult profoundly deaf subjects. Tests of tactile- visual speech perception and lipreading will be conducted at pre-, mid-, and post-test times, and weekly lipreading training will be given over an 18-month period. Project III, years 1-4, uses computational and statistical methods to analyze errors made in lipread sentences. Normal hearing and hearing impaired subjects will be tested in a study on individual differences among lipreaders. Project III will result in a model of sentence lipreading and design for clinical assessment materials. Now that tactile aids are being produced commercially and scientific and clinical debates are taking place concerning the benefits of tactile vs. cochlear implant supplements for speech communication, research must go beyond questioning whether tactile aids can help to questions of how they work, their limitations, their long-term effects on perception, and methods for accurate of potential users.